T-type switching system for broadband switching system and time switching stage for use in a t-stage

Abstract

If in a broadband switching system broadcast TV-signals are switched, then it should be preferred that they can be switched through without the risk of blocking. To achieve this it is proposed to distribute the broadcast TV-signals via a p-fold bus line (BUS 1 , . . . BUS 64 ) over the 64 inputs (DTV 1 , . . . DTV 64 ) of the information stores IM 1 , IM 2 , . . . IM 256 . Together with their associated addressing and control, these information stores IM constitute a T-type T-stage switching system. Multiplex signals coming, for example, from the series-parallel converters SPT 1 , SPT 2 , . . . of an S-stage of a TST switching system are applied to the further, for example 36, inputs (I out ,1, . . . I out ,36) of each information store IM. By the action of the time slot control and the addressing associated with each information store IM 36 of the 100 memory locations are read and the contents are applied to the subscribers via outgoing multiplex line OMT. An advantage applied is that all the desired broadcast-TV channels can be switched-through free from blocking.

We claim: 
     
       1. A switching system of the T-type, comprising n parallelarranged time switching stages each comprising an information store having N addressable memory locations and an addressing arrangement connected thereto, the switching system being controlled by a time slot control, characterized in that the T-type switching system includes a p-fold bus line, that each bus line has one end connected during each time slot to an input of each of the information stores and its other end is connectable during each time slot to one of the p possible signal sources for distributing the p signals from all of the p signal sources to p inputs of all the n time switching stages, that the information store of each time switching stage has q further inputs for individually connecting a total of n×q further signal sources and that the time switching stages are each arranged for exchanging N 1  (N 1  <N) time slots. 
     
     
       2. A time switching stage in a switching system of the T-type as claimed in claim 1, wherein said switching stage includes an information store having addressable memory locations, an addressing arrangement connected thereto and controlled by a time slot control, characterized in that the information store has N memory locations, that the time slot control is arranged for cyclically generating each time N 1  addresses (N 1  <N) and that an outgoing multiplex line connected to the information store contains frames of N 1  time slots each